Expansion joint system

Abstract

An expansion joint system for bridging a gap between spaced apart structural members and for accommodating transverse movement. The expansion joint system includes a plurality of finger plates carrying a plurality of elongated fingers that are configured to at least partially extend across an expansion joint gap from opposing structural members. The finger plates are pivotably mounted to the underlying structural members to permit pivoting or rotating movement in the transverse direction. A torsion spring is engaged with the pivotable finger plates and provides a restoring force to the finger plate when the finger plate rotates relative to the spring. Also disclosed is an expansion joint including spaced-apart structural members and the expansion joint system installed in the joint. The elongated fingers of the finger plates of the expansion joint system extend at least partially across the expansion joint gap from a first structural member and are interdigitated with elongated fingers extending from a opposing second structural member to provide a surface to traverse the expansion joint gap.

The invention claimed is: 
     
       1. An expansion joint system comprising:
 a first support; 
 a first plate comprising a plurality of fingers pivotally engaged with said first support; 
 a first spring engaged with said first plate; 
 a second support; 
 a second plate comprising a plurality of fingers pivotally engaged with said second support; 
 a second spring engaged with said second plate; 
 wherein said first plurality of fingers and said second plurality of fingers are interdigitated and are located in a plane; 
 wherein said first plate and said second plate can pivot in a transverse direction in the plane; and 
 wherein said first spring provides a restoring force to said first plate and said second spring provides a restoring force to said second plate to return said first and second finger plates to the neutral position in response to said first and second plates pivoting in the transverse direction. 
 
     
     
       2. The expansion joint system of  claim 1 , wherein said first and second supports comprise elongated C-shaped channels. 
     
     
       3. The expansion joint system of  claim 2 , wherein said first and second supports comprise a pair of opposite facing elongated C-shaped channels. 
     
     
       4. The expansion joint system of  claim 1 , wherein each of said first and second finger plates comprise a base portion and said plurality of fingers extend along a longitudinal axis from said base portion. 
     
     
       5. The expansion joint system of  claim 4 , wherein said plurality of fingers of at least one of said first and second finger plates comprise three elongated and spaced-apart fingers. 
     
     
       6. The expansion joint system of  claim 5 , wherein at least one of said plurality of fingers of said first and/or second finger plates further comprises at least one finger bearing engaged with an end of the at least one of said plurality of fingers opposite of said base portion of said first and/or second finger plates. 
     
     
       7. The expansion joint system of  claim 6 , wherein said bearing comprises a substantially cylindrical portion and axially aligned guide portions extending from said cylindrical portion. 
     
     
       8. The expansion joint system of  claim 7 , wherein said at least one finger bearing comprises a polyurethane. 
     
     
       9. The expansion joint of  claim 5 , wherein said base portion of said first and second finger plates comprises opposite facing top and bottom surfaces and further comprises a first recess formed in said bottom surface. 
     
     
       10. The expansion joint system of  claim 9 , further comprising at least one finger plate bearing engaged with said first recess of at least one of said first and second finger plates and supporting said base portion of said finger plates. 
     
     
       11. The expansion joint system of  claim 10 , wherein said at least one finger plate bearing comprises a polyurethane bearing. 
     
     
       12. The expansion joint system of  claim 5 , further comprising a second recess in said bottom surface of said base portion of said first and second finger plates and wherein said recess is non-circular. 
     
     
       13. The expansion joint system of  claim 12 , wherein said non-circular recess is square shaped. 
     
     
       14. The expansion joint system of  claim 1 , wherein said first and second springs are engaged with a rigid top portion and a rigid bottom portion. 
     
     
       15. The expansion joint system of  claim 14 , wherein said rigid top portion comprises a non-circular portion which engages said non-circular recess of said first and second finger plates. 
     
     
       16. The expansion joint of  claim 1 , wherein said first and second springs are torsional springs and provide a torsional restoring force to said first and second finger plates when said finger plates pivot in the transverse direction. 
     
     
       17. The expansion joint system of  claim 1 , further comprising fasteners comprising an elongated bolt having a head and a threaded portion, wherein said head of said fasteners engages said first and/or second finger plates, and wherein said threaded portion of said fasteners threads into said spring. 
     
     
       18. An expansion joint comprising:
 a first structural member; 
 a second structural member spaced-apart in the longitudinal direction from said first structural member; 
 a first support mounted to said first structural member; 
 a first plate comprising a plurality of fingers pivotally engaged with said first support; 
 a first spring engaged with said first plate; 
 a second support; 
 a second plate comprising a plurality of fingers pivotally engaged with said second support; 
 a second spring engaged with said second plate; 
 wherein said first plurality of fingers and said second plurality of fingers are interdigitated and are located in a plane; 
 wherein said first plate and said second plate can pivot in a transverse direction in the plane; and 
 wherein said first spring provides a restoring force to said first plate and said second spring provides a restoring force to said second plate when said first and second plates pivot in the transverse direction. 
 
     
     
       19. The expansion joint of  claim 18 , comprising a plurality of first and second finger plates positioned in a side-by-side arrangement along the transverse axis of said expansion joint. 
     
     
       20. The expansion joint of  claim 19 , wherein said plurality of fingers of said first and second finger plates extend across said gap from said first and second structural members, and wherein said plurality of fingers of said first finger plate extending from said first structural member are interdigitated with said plurality of fingers of said second finger plate extending from said second structural member. 
     
     
       21. The expansion joint of  claim 20 , wherein said first and second finger plates are pivotally mounted to said structural members with fasteners. 
     
     
       22. The expansion joint of  claim 21 , further comprising a rotation prevention member engaged with said first and second springs to prevent said springs from rotating with said first and second finger plates. 
     
     
       23. The expansion joint of  claim 22 , further comprising fasteners passing through said first and second finger plates and into said first and second springs. 
     
     
       24. The expansion joint of  claim 18 , wherein said first and second supports comprise elongated C-shaped channels. 
     
     
       25. The expansion joint of  claim 24 , wherein said first and second support comprise a pair of opposite facing elongated C-shaped channels. 
     
     
       26. The expansion joint of  claim 25 , wherein said first and second springs are independently engaged with said first and second supports. 
     
     
       27. The expansion joint of  claim 26 , wherein a support plate is mounted to said first and second supports by fasteners. 
     
     
       28. An expansion joint for a bridge or roadway comprising:
 a first bridge or roadway structural member; 
 a second bridge or roadway structural member spaced-apart in the longitudinal direction from said first bridge or roadway structural member; 
 a first support mounted to said first bridge or roadway structural member; 
 a first plate comprising a plurality of fingers pivotally engaged with said first support; 
 a first spring engaged with said first plate; 
 a second support mounted to said second bridge or roadway structural member; 
 a second plate comprising a plurality of fingers pivotally engaged with said second support, 
 a second spring engaged with said second plate; 
 wherein said first plurality of fingers and said second plurality of fingers are interdigitated and are located in a plane, 
 wherein said first plate and said second plate can pivot in a transverse direction in the plane, and 
 wherein said first spring provides a restoring force to said first plate and said second spring provides a restoring force to said second plate when said first and second plates pivot in the transverse direction.